ATM communications system for transmitting internet data packets

ABSTRACT

Components for transmitting ATM cells related to Internet data packets are additionally integrated in an ATM communications system for transmitting data and data packets packed in ATM cells for ATM communications networks which are formed by ATM communications systems. The complete integration of the Internet transmission function into ATM communications systems results in effective traffic and network management of ATM cells related to Internet data packets with a very low level of integration complexity.

With the increasing importance of the Internet or “World Wide Web”, theInternet protocol is increasingly influencing the design of existing andfuture communications networks. The currently used and standardizedInternet protocol—in particular Internet Protocol Version 4—ispacket-oriented, that is to say the information to be transmitted ispacked into data packets. These Internet data packets are in each casepreceded by an Internet data packet header, in which a source anddestination address, comprising 32 bytes, is stated. 128 bytes areprovided for both the source address and the destination address in afuture planned version. With the aid of a current or a future Internetprotocol, a communication link is produced between Internetcommunications terminals, that is to say in particular computers, withthe communications terminals being connected directly via“point-to-point” data links.

Owing to the considerable rate of growth of the Internet, additionalinfrastructures need to be provided for this purpose, and thecommunications networks need to be adapted or added to. One possibleadaptation is represented by Internet switching devices—called routersor gateways in the specialist world and referred to as routers in thefollowing text—which are used in the edge region of communicationsnetworks as access routers or gateways (edge routers) and, in thecommunications network itself, as special Internet routers.Communications network concepts for the transmission of Internet datapackets in which the routers are produced using ATM technology(Asynchronous Transfer Mode) have been under discussion for a long time.In this case, in the access routers or else in the access networkassociated with the access router, the Internet data packets are packedin ATM cells and transmitted, via the ATM communication network, tospecial Internet ATM routers. These Internet ATM routers are connectedto specific ATM communications systems in the ATM communications networklike a server, and provide a virtual Internet overlay network which issuperimposed on the ATM communications network, with the Internet ATMrouters essentially being connected via permanent virtual connections(PVC) and semi-permanent virtual connections (SPVC).

This concept with additional “edge” routers and special ATM routers inATM communications networks means that, with increasing acceptance andwidening use of the Internet, there will be, owing to the additionalrouting functions in the ATM communications systems to and from theInternet ATM routers, a considerable additional traffic load on the ATMcommunications systems in the ATM communications networks, leading to areduction in the transmission service for the data and data packets forother services.

EP 0 597 487 A2 discloses a communications system in which data packedinto ATM cells and data packets packed into ATM cells are transmittedvia an ATM switch. For transmission of ATM cells related to Internetdata packets from the ATM cell stream, the destination addressinformation for the Internet data packets is transmitted to the ATMcommunications system from a connected ATM communications terminal withthe aid of a special ATM cell. Routing information is derived from thedestination address information in the ATM communications system. Thederived routing information is then inserted into each ATM cell in anInternet data packet, for transmission via an ATM communicationsnetwork.

The document IEE, 1996, Flow Labelled IP: A Connectionless Approach toATM, Peter Newman et al. discloses an ATM communications network inwhich a local area network LAN is emulated for the connection ofinternet communications terminals. A “Connectionless ATM” is providedfor the transmission of the Internet data packets. Within the ATMcommunications network, signalling in accordance with the ATM AdaptionLayer (AAL-5) is provided in the ATM communications systems.

The object on which the invention is based is to improve the integrationof Internet in ATM communications networks. The object is achieved bythe features of claim 1.

The major aspect of the invention is that the ATM communications systemsfor transmitting data and data packets packed into ATM, cells areadditionally provided, for transmitting Internet data packets, withmeans for selecting ATM cells related to Internet data packets from theATM cell stream, means for finding Internet data packet headers from theselected ATM cells and means for extracting the destination addressinformation contained in Internet data packet headers. Additional meansare advantageously provided for sorting the transmitted ATM cells toform the respective Internet data packets and means for collecting thesorted ATM cells on the basis of specific Internet data packets and forpassing on Internet data packet ways.

The complete integration of the Internet routing function in the ATMcommunications systems allows the ATM cell stream within the ATMcommunications network to be considerably reduced, since there is noneed for the Internet data packets to be routed, possibly via a numberof ATM communications systems, to the relevant Internet ATM routers.This means that it is possible to dispense entirely with the InternetATM routers, and the integration of the Internet routing function in theATM communications systems can be achieved with little additionalcircuitry and programming complexity. The already existing components ofthe ATM communications systems remain unchanged, that is to say they donot need to be modified.

The integration results in very short delays for the Internet datapackets to be transmitted, since there is no routing to Internet ATMrouters. A further advantage can be seen in integration, in particularretrospective integration, in that there is no effect on ATM trafficthat is not related to Internet data packets. Furthermore, a universalATM communications network can be provided for various types of trafficand service, which can be configured and matched to the respectiverequirements with very little effort, depending on user requirements,and the Internet routing function can be retrofitted or removed at anytime.

For integration of the additional means for transmitting ATM cellsrelated to Internet data packets, these are advantageously assigned tothe individual system components as a function of the systemarchitecture of the ATM communications system—claim 3. In this case,both the concept of the ATM communications system with ATM multiplexers,line termination units, ATM switching networks and alternatively fromATM statistics multiplexers, and the fundamental ATM switching principlewithin the ATM communications system need to be taken into account—forexample the self-routing principle using communications-system internalheaders and a connection identification. It is particularly advantageousfor the additional means for transmitting ATM cells related to Internetdata packets to be integrated between the communications connections andthe ATM switching network—claim 4—, since, in this case, the integrationtakes place directly in the data path, that is to say in the existingtransmission path for ATM cells. Transmission of additional informationfor determining the routing information within the ATM communicationssystem is largely avoided with such integration.

Five advantageous implementation versions—claims 5 to 9—are possible forthe integration of the additional means for transmitting ATM cellsrelated to Internet data packets, which are based on an ATMcommunications system concept in which line units which provide ATMcommunications connections are connected to at least one ATM multiplexerfor multiplexing ATM cells transmitted by the line units, and at leastone ATM statistics multiplexer, which is connected on the input side toATM multiplexers, is provided for buffer storage and for statisticaldistribution of the ATM cells, as well as an ATM switching network whichis connected to the at least one ATM statistics multiplexer.

The most advantageous integration in an ATM communications systemconceived in such a way is represented by the integration of theadditional means for transmitting ATM cells related to Internet datapackets in the stastistics multiplexer—claim 6. In this case, a singlebuffer store can advantageously be used for the buffer storage of ATMcell queues not only for ATM cells related to Internet data packets butalso for ATM cells which are not related to Internet data packets, andthe existing means for inserting ATM cells to be transmitted to the ATMswitching network or to the ATM multiplexer are also used. Furthermore,[lacuna] are included by the integration of the additional means fortransmitting ATM cells related to Internet data packets into the TrafficManagement and Quality of Service Procedures, which have beenstandardized at the ATM forum and are implemented in the ATM statisticsmultiplexer. In this case, the Internet links can be included on thebasis of their service class in the overall concept of the ATMcommunications system for handling ATM links in different classes—forexample “real time” or “non-real time” links with an UBR (unspecifiedbitrate), ABR (available bitrate) etc., as a result of which theintegration complexity is considerably reduced.

One advantageous development of the communications system according tothe invention can be seen in that, for transmitting ATM cells related tothe Internet with predetermined, virtual path information and/or virtualchannel information, means are provided for selecting ATM cells relatedto Internet data packets as a function of the predetermined virtual pathinformation and/or virtual channel information—claim 13. The assignmentor specification of specific virtual paths for Internet data packetsallows an advantageous implementation for the indentification of ATMcells related to Internet data packets. When transmitting using theself-routing principle and when transmitting ATM cells related toInternet data packets using predetermined routing information (which isderived from the virtual path information and/or virtual channelinformation and is internal to the communications system) and aconnection identification, means are provided for selecting ATM cellsrelated to Internet data packets as a function of the predeterminedrouting information (which is internal to the communications system),and a connection identification—claim 14.

According to a further advantageous refinement of the ATM communicationssystem according to the invention, the means for extracting thedestination address information contained in Internet data packetheaders comprise means for finding the destination address informationinserted in the Internet data packet headers and means for passing onthe destination address information to the means for deriving routinginformation from the destination address information—claim 15. Thesemeans are normally implemented as programs in the ATM statisticsmultiplexer.

According to a development of the ATM communications system according tothe invention in that the following items are provided for ATM cellsrelated to Internet data packets with Internet multicast destinationaddress information in the Internet data packet header: means forassigning further routing information to Internet multicast destinationaddress information in the routing table, and means for copying therespective ATM cells and for introducing in each case one furtherrouting information item—claim 19. Storage of a number of communicationsnetwork routing information items relating to Internet destinationaddress information makes it possible to copy and transmit ATM cellsrelated to Internet data packets to a number of ATM communicationssystems in the ATM communications network, in which case further“multicast” routing information is determined and inserted in the ATMcommunications systems which have received these ATM cells, possiblyafter further assessment of the Internet destination addressinformation.

Further advantageous refinements of the invention can be found in thefurther claims.

The invention will be explained in more detail in the following textwith reference to three block diagrams, in which:

FIG. 1 shows a block diagram of the structure of an ATM communicationssystem,

FIG. 2 shows a block diagram of the integration of the Internet routingfunction between and ATM multiplexer and an ATM statistics multiplexerin the communications system shown in FIG. 1, and

FIG. 3 shows a block diagram of the integration of the Internet routingfunction in the ATM statistics multiplexer in the communications systemshown in FIG. 1.

FIG. 1 shows an ATM communications system ATM-KS which, as a centralswitching component, has an ATM switching network ASN. The ATM switchingnetwork ASN represents a multistage ATM switching matrix which, in thevarious levels, comprises switching elements with queue controllers forthe transmission of real time and non-real time ATM cells. For thispurpose, the switching elements contain buffer stores or buffers, whichare used to control the output queues. The ATM switching network ASNhas, for example, eight 2.4 Gbit/s inputs E, to each of which an ATMstatistics multiplexer SMU can be connected.

The ATM statistics multiplexer SMU has ingress and egress multiplexfunctions and units I-SMU,E-SMU, with the ingress function beingprovided for handling the ATM cells to the ATM switching network ASN andthe egress function being provided for handling the ATM cells from theATM switching network ASN. The ATM statistics multiplexer, SMU providesATM cell traffic management in particular for the Quality, of Servicefunctions. In the case, for example, of the “Quality of Service” whichhas been standardized at the ATM forum, a distinction is drawn, forexample, between the real time and non-real time traffic classes orlinks with an UBR (unspecified bitrate), ABR (available bitrate) etc.,for which the relevant ATM cells are in each case statisticallymultiplexed in different queues. A large buffer store or buffer isprovided for the ATM cell traffic management, and is controlled with theaid of complex buffer management and ATM cell scheduling.

The ATM statistics multiplexers SMU are connected via appropriate inputsto an ATM multiplexer AMX, whose inputs E are each connected to a linetermination unit LIC. The line termination units LIC each have an outputwith a transmission speed of, for example, 155 Mbit/s and provide acommunications connection KA to which ATM cells which are related toInternet data packets and ATM cells which are not related to Internetdata packets are passed, for example, from Internet communicationsdevices. The line termination units LIC are designed, for example, forthe connection of ATM communications systems or ATM communicationsterminals—not illustrated—in which case it is also possible to connectATM communications terminals using Internet protocols or Internetfunctions. The Internet data packets IDP as well as non-Internet datapackets DP from the other ATM communications devices are inserted intoATM cells Z′Z, with the transmission addresses of the Internet datapackets IDP being represented by an Internet source and destinationaddress DA by means of a [lacuna] in the cell header of the respectiveInternet data packet. The ATK cells Z′ related to Internet data packetsare defined as such by predetermined virtual path information PVI (whichis predetermined when the connection is being set up and ispredetermined during the connection) and/or virtual channel informationVCI, that is to say the virtual paths or channels for the Internet aredefined—indicated by ZS(Z,Z′ (VPI,VCI) in FIG. 1.

In the line termination unit LIC, routing information KRI which isinternal to the communications system and connection identifications CIare derived on a connection-specific basis from the virtual path andchannel information VPI, VCI of the ATM cells Z′ related to Internetdata packets, for self-routing of said ATM cells Z,Z′ in the ATMswitching network ASN, are preceded in an additional cell header ZK forthe respective ATM cell Z,Z′ and are passed on via the ATM multiplexerAMX to the ATM statistics multiplexer SMU—indicated in FIG. 1 by ZS(Z,Z′(KRI,CI).

FIG. 1 also shows five versions relating to the integration of the meansfor transmitting ATM cells (Z′) related to Internet data packets in theATM communications system ATM-KS. This shows all the envisaged meansRE-R,PE-R,EX-R,ZSP,RE,EF-R,SO-R,AS-R for the transmission of Internetdata packets PD by rectangles with dashed lines, with the meansRE-R,PE-R,EX-R,ZSP,RE,EF-R,SO-R,AS-R being implemented between ATMmultiplexer AMX and ATM statistics multiplexer SMU or in the ATMstatistics multiplexer SMU, or being assigned to the ATM switchingnetwork ASN. The dashed-dotted rights comprise all the meansRE-R,PE-R,EX-R,ZSP,EF-R,SO-R,AS-R for transmitting ATM cells Z′ relatedto Internet data packets apart from the means RE for deriving routinginformation RI (which has been received by the means for extractingdestination address information DA) from the destination addressinformation DA and for passing it on to the means ZK-U for inserting therouting information RI into each ATM cell Z′. In other ATMcommunications system structures, for example without ATM statisticsmultiplexers SMU, the means RE-R,PE-R,EX-R,ZSP,EF-,SO-R,AS-R fortransmitting ATM cells Z′ related to Internet data packets may also bearranged or implemented in the remaining components, that is to say inthe ATM multiplexer AMX or in the line termination units LIC.

FIG. 2 and FIG. 3 show the two most advantageous implementationversions, in which all the envisaged meansRE-R,PE-R,EX-R,ZSP,RE,EF-R,AS-R,SO-R for transmitting Internet datapackets IPD are arranged between the ATM multiplexer AMX and the ATMstatistics multiplexer SMU—FIG. 2—or in the ATM statistics multiplexerSMU—FIG. 3.

FIG. 2 and FIG. 3 will be explained together in the following text,since a number of components and means are implemented in the same way,that is to say have identical functions, with one ingress unit I-SMUbeing shown in each case, and the engress function also being explainedwith reference to FIG. 2 and FIG. 3. The figures each shown an inputmodule EM, in which a cell identification routine ZE-R which identifiesATM cells Z′ related to Internet data packets, and an Internet packetheader identification routine PE-R, which identifies the Internet packetheaders IH of the Internet data packets IDP, is implemented. Theidentification of ATM cells Z′ related to Internet data packets iscarried out in the exemplary embodiment using the predetermined routinginformation KRI which is internal to the communications system, and theconnection identifications VI. Those ATM cells Z which are not relatedto Internet data packets are passed on, in FIG. 2, bypassing thearrangement according to the invention to an output module AM, in which,using an insert routine EF-R implemented in this module, ATM cells Z,Z′related to Internet data packets, related into the non-Internet datapackets are joined together or multiplexed once again to form an ATMcell stream ZS(Z,Z′). In FIG. 3, only the real time ATM cells Z whichare to be passed on immediately are passed on to the output module.

The ATM cells Z′ related to Internet data packets are buffer stored in acell memory ZSP while the Internet packet header IH is being processed,this cell memory ZSP being formed by a memory SP and a memory controllerSPV. The Internet packet headers IH are passed on to a router moduleRT-M, in which an extractor routine EX-R and a routing unit RE isimplemented. Using the extraction routine EX-R, the Internet destinationaddresses DA contained in the Internet packet headers IH are extracted,that is to say they are read from an address destination field whichcomprises, for example in accordance with the standardized InternetProtocol Version 4, the 32 bytes, or only the relevant field elementsare read, and are passed on to the routing unit RE. In the routing unitRE, a routing table RT is used to determine routing information RIrelated to the ATM communications network, and this is transmitted tothe memory controller SBV. In the routing table RT, each Internetdestination address DA is assigned routing information RI related to theATM communications network, in which case the routing information RIdefines that further ATM communications system ATM-KS to which therespective Internet data packet IDP is to be transmitted. A preconditionfor this is the mapping of the Internet onto the ATM communicationsnetwork, that is to say the Internet switching points are mapped ontothe ATM communications network. The routing information RI is in thiscase formed taking account of the ATM transmission principle used, forexample the self-routing principle, that is to say as routinginformation KRI which is internal to the communications system, and asconnection identification CI. The routing information RI is transmittedvia the memory controller SPV to a cell header converter ZK-U, and thisis used to insert the routing information RI into every ATM cell Z′,which is transmitted from the memory SP at the right time, in therelevant Internet data packet IPD.

Furthermore, a unique packet identification PK is allocated for eachInternet data packet IPD with the aid of the memory controller SPV and,using the cell header converter ZK-U, is inserted into every ATM cell Z′in the respective Internet data packet IDP. In the exemplary embodiment,the packet identification PK is inserted into the additional cell headerZK of an ATM cell Z′. In this case, the start of an Internet data packetIDP is determined by identifying a data packet end identification (notillustrated) which is inserted into the ATM cell header ZK—particularlyin the case of ATM cells in accordance with the standardized ATMAdaption Layer AAL 5—, and the data contained in the following ATM cellZ′ are defined as the Internet data packet start and as the first ATMcell Z′ of a following Internet data packet IDP, which is provided witha new, unique packet identification PK. If the ATM cell headers arestructured differently, different methods must be provided fordetermining the different Internet data packets IDP, for example searchfor Internet data packet headers or parts of them.

In the ATM communications system ATM-KS according to the invention, therouting information VIP, VCI and the converted routing information KRIwhich is internal to the communications system as well as the connectionidentification CI are terminated, and the Internet destination addressDA of the respective Internet data packet IDP is used to form therouting information RI (which implements an Internet routing function)for the ATM communications network, with the Internet being mapped bythe routing information RI onto the ATM communications network—indicatedin FIG. 1 by Z′ (RI(KRI,CRI).

The additionally engress functions are implemented by a sorting routineSO-R and by a collection routine AS-R and by the memory controller SPV.In this case, the ATM cells Z′ which are transmitted by the ATMswitching network ASN via the input module EM, are stored in the memorySP and relate to Internet data packets are sorted into Internet datapackets IDP with the aid of the packet identifications PK which are alsotransmitted, into Internet data packets IDP corresponding to the packetidentification PK, and a complete inter-data packet IDP is in each casecollected with the aid of the collection routine AS-R.

The cell header converter ZK-U is then used to convert the routinginformation KRI which is internal to the communications system and theconnection identification CI into virtual path and channel informationVPI, VCI which is specific to the communications network, and.the ATMcells Z′ which have been provided with converted routing information RIare inserted in the form of Internet data packets and with the aid ofthe insertion routine EF-R into the ATM cell stream ZS which has the ATMcells Z which are already not related to Internet data packets. This ATMcell stream ZS passes via an ATM multiplexer AMX and via a linetermination unit LIC to a further ATM communications system which isdefined by the routing information RI.

In the integration shown in FIG. 3, all the ATM cells Z apart from thereal time cells are supplied to a cell management device ZME in which,taking into account the standardized “Quality of Service” aspects, theATM cells Z are statistically multiplexed into the respective “Qualityof Service” specific queues. A two-staged scheduling concept isenvisaged for the implementation of these, functions, in which case aportion of the queues is in each case logically formed and multiplexedin a plurality of scheduler block SB and a higher-level scheduler SBS,and are also called up for passing on, in which case the ATM cells Z,Z′are themselves buffer-stored in the memory SP, and the routinginformation RI is inserted in the cell header converter ZK-U.

We claim:
 1. An ATM communications system for transmitting ATM cells ofan ATM cell stream, said ATM cell stream comprising data packets packedinto ATM cells or ATM communications networks formed by ATMcommunications systems, said ATM communications system comprising thefollowing items for the transmission of ATM cells related to Internetdata packets: a cell identification routine for selecting said ATM cellsrelated to Internet data packets from said ATM cell stream, an Internetpacket header routine for finding Internet data packet headers from saidATM cells related to Internet data packets, an extractor routine forextracting destination address information contained in said Internetdata packet headers, a routing unit for deriving derived routinginformation from said destination address information, and an insertioncomponent comprising a cell header converter, a cell memory, and aninsertion routine wherein said insertion component inserts said derivedrouting information into each said ATM cell of an Internet data packet,for transmission via the ATM communications network, wherein basetransmittal components are comprised of said cell identificationroutine, said Internet packet header routine, said extractor routine,said insertion component, and said routing unit.
 2. The ATMcommunications system as claimed in claim 1, further comprising: asorting routine for sorting transmitted said ATM cells to formrespective said Internet data packet; and a collection routine forcollecting said stored ATM cells on the basis of individual saidInternet data packets and or passing them on as said Internet datapackets, and wherein core transmittal components are comprised of saidbase transmittal components, said sorting route, and said collectionroute.
 3. The ATM communications system as claimed in claim 2, whereinsaid core transmittal components used for transmitting said ATM cellsare assigned to individual system components.
 4. The ATM communicationssystem as claimed in claim 2, wherein said core transmittal componentsfor transmitting said ATM cells related to said Internet data packetsare arranged between ATM communications connections of said ATMcommunications system and its ATM switching network.
 5. The ATMcommunications system as claimed in claim 2, further comprising amultiplexer arrangement, said multiplexer arrangement comprising: lineunits which provide ATM communications connections, wherein said lineunits are connected to at least one ATM multiplexer for multiplexingsaid ATM cells transmitted by said line units, at least one ATMstatistics multiplexer which is connected on an input side to said atleast one ATM multiplexers for buffer storage and statisticaldistribution of said ATM cells, and an ATM switching network which isconnected to said at least one ATM statistics multiplexer.
 6. The ATMcommunications system as claimed in claim 5, wherein said coretransmittal components related to said Internet data packets areintegrated in said statistics multiplexers.
 7. The ATM communicationssystem as claimed in claim 5, wherein said core transmittal componentsrelated to said Internet data are assigned to said ATM switching network(ASN).
 8. The ATM communications system as claimed in claim 1, furthercomprising: a memory controller for unique identification of said ATMcells in an Internet data packet which is to transmitted, and a sortingrouting for sorting the transmitted said ATM cells to form saidrespective Internet data packets as a function of said uniqueidentification.
 9. The ATM communications system as claimed in claim 1,further comprising: an Internet data packet transmission routine fortransmitting said ATM cells in, in each case, one said Internet datapacket to an output of said ATM switching network.
 10. The ATMcommunications system as claimed in claim 1, further comprising: apacket-oriented transmission routine for transmitted said ATM cellsrelated to said Internet data packets which can be implemented fordifferent Internet protocols using packet-oriented informationtransmission.
 11. The ATM communications system as claimed in claim 1,where said extractor routine comprises: an extractor finding routine forfinding said destination address information inserted in said Internetdata packet headers, and an extractor forwarding routine for passing onsaid destination address information to said routine unit.
 12. The ATMcommunications system as claimed in claim 1, wherein said extractorroutine is designed for different Internet data packet headers.
 13. TheATM communications system as claimed in claim 1, wherein said routingunit further comprises; a routing table, and search routine whichsearches said routing table.
 14. The ATM communications system asclaimed in claim 1, wherein said routing information is represented byrouting information which maps the Internet onto said ATM communicationsnetwork and is related to said ATM communications network, and saidrouting information is represented together with a connectionidentification identified by identification information selected fromthe group consisting of: 1) virtual path information, and 2) virtualchannel information, and routing information, said routing informationbeing internal to said ATM communications system, wherein said routinginformation is converted, together with a connection identification,into said identification information before being passed on to said ATMcommunications network.
 15. The ATM communications system as claimed inclaim 1, for said ATM cells related to Internet data packets which haveInternet multicast destination address information in said Internet datapacket header, further comprising: an assignment routine for assigningfurther routing if information to said Internet multicast destinationaddress information in a routing table, and a copying routine forcopying respective said ATM cells and for introducing in each case onefurther routing information item.
 16. The ATM communications system asclaimed in claim 1, further comprising: an ATM cell buffer store forbuffer storage of said ATM cells during the processing of switchingprocedures, and for passing on said selected ATM cells in a way whichconforms with an ATM cell stream, wherein said cell buffer store isutilized when transmitting ATM cells related to Internet data packets.17. The ATM communications system as claimed in claim 1, wherein saidbase transmittal components are designed in accordance with thestandardized ATM adaption layer AAL 5, wherein said ATM cells mayinclude packet end information which indicates the end of a data packet,wherein said data packet may be an Internet data packet.
 18. The ATMcommunications system as claimed in claim 5, wherein said coretransmittal components related to said internet data packets areprovided between said ATM multiplexers and said ATM statisticsmultiplexes.
 19. The ATM communications system as claimed in claim 18,wherein assigned to said ATM switching network, said routing unitpassing said derived routing information, derived from said destinationaddress information extracted by said routine, on to said insertioncomponent.
 20. The ATM communications system as claimed in claim 19,wherein said core transmittal components related to said Internet datapackets are integrated in said ATM statistics multiplexer.
 21. The ATMcommunications system as claimed in claim 1, further comprising, apath-channel cell selection routine for selecting said ATM cells relatedto said Internet data packets wherein said path-channel cell selectionroutine operates on Internet data packet information selected from thegroup consisting of predetermined virtual path information and virtualchannel information, when transmitting ATM cells related to the Internetwith predetermined information cells selected from the group consistingof cells with predetermined virtual path information cells withpredetermined virtual channel information.
 22. The ATM communicationssystem as claimed in claim 1, further comprising: a routing cellselection routine for selecting ATM cells related to said Internet datapackets, wherein said routing cell selection routine operates onpredetermined routing information and a connection identification,wherein said predetermined routing information is internal to said ATMcommunications system, when transmitting ATM cells related to Internetdata packets using said predetermined routing information, wherein saidpredetermined routing information is internal to said ATM communicationssystem, and is derived from: 1) Internet data packet informationselected from the group consisting of predetermined virtual pathinformation and virtual channel information, and 2) said connectionidentification.